| 摘要 |
PURPOSE:To use effectively an operation panel by changing over automatically the passing band width of an intermediate frequency amplifier to the wide band when a stereo broadcasting is received, and to the narrow band when the monoral broadcasting is executed, with the information obtained by the output of the stereo indicator. CONSTITUTION:An intermediate frequency band change-over device 4 selects one side input side 4A of the intermediate frequency band change-over device 4 when an intermediate band changeover control input 4c is a low level, and other side input side 4B when the input is a low level, and either of the wide band intermediate frequency or the narrow band frequency is outputted to the output 4D. A stereo demodulator 5 demodulates a stereo composite signal to the right and left sound signals, and at the time of receiving the stereo signal, an stereo indicator 6 lights up. The output of the stereo indicator 6 goes to the intermediate frequency band change-over control input 4C, and at the time of receiving the stereo signal, a low level is obtained and at the time of receiving the monoral signal, the high level is obtained and an intermediate frequency band width is automatically changed over. Thus, a malfunction and change-over forgetting are removed, the receiving can be always executed in the best condition and the operation panel can be made simple. |
